It is widely known that tobacco smoke contains mutagenic and carcinogenic compounds which cause substantial morbidity and mortality to smokers. Examples of such substances include polycyclic aromatic hydrocarbons (PAH) and nitrosamines.
Polycyclic aromatic hydrocarbons appear to cause toxicity by intercalating within DNA molecules. Nitrosamines are electrophilic, alkylating agents which are potent carcinogens. Nitrosamines are not present in fresh or green tobaccos and are not formed during combustion. They are instead formed by reactions involving free nitrate during processing and storage of tobacco, or by the post-inhalation, metabolic activation of secondary amines present in tobacco smoke.
Attempts to reduce the amount of toxic and mutagenic compounds that reach the smoker include tobacco smoke filters positioned between the burning tobacco and the smoker.
Conventional filters are made of cellulose acetate, with or without activated charcoal. These conventional filters, however, are only partially effective in reducing the amount of toxic and mutagenic compounds reaching the smoker. Further, conventional filters disadvantageously remove flavor compounds, thereby decreasing acceptance by the smoker.
There is, therefore, a need for an improved filter for a smokable device that substantially removes toxic and mutagenic compounds from tobacco smoke. Further, there is a need for an improved filter which allows the passage of flavor compounds while substantially removing toxic and mutagenic compounds from tobacco smoke. Such an improved filter would preferably be simple and inexpensive to manufacture, and convenient to use.
The present invention is directed to a tobacco smoke filter that meets these needs. In one embodiment, there is provided a method of making a first tobacco smoke filter segment. The method comprises the steps of, first, providing one or more than one copper-containing porphyrin. Then, a mixture of cellulose fiber and the copper-containing porphyrin is produced. Next, the mixture is heated for a sufficient time at one or more than one temperature sufficient to covalently link the copper-containing porphyrin to the cellulose fiber. Then, the cellulose fiber with covalently bound, copper-containing porphyrin is formed into the first tobacco smoke filter segment.
In one embodiment, the copper-containing porphyrin provided is a copper phthalocyanine. In a preferred embodiment, the copper-containing porphyrin provided is C.I. Reactive Blue 21 dye. In another embodiment, the mixture of cellulose fiber and the copper-containing porphyrin produced comprises a ratio of about 1.2:10 copper-containing porphyrin to cellulose fiber by weight. In a preferred embodiment, the mixture of cellulose fiber and the copper-containing porphyrin further comprises sodium sulfate and chlorine water.
In one embodiment, The method further comprises rinsing the mixture of cellulose fiber with covalently bound, copper-containing porphyrin after heating the mixture. In another embodiment, the method further comprising adding one or more than one additional substance to the cellulose fiber with covalently bound, copper-containing porphyrin. In one embodiment, the one or more than one additional substance is selected from the group consisting of activated charcoal, chitin and lignin. In another embodiment, the one or more than one additional substance is selected from the group consisting of an antioxidant, dry water, a humectant, microcapsules, a radical scavenger, a surfactant and combinations of the preceding.
According to one embodiment, there is provided a method of making a smokable device. The method comprises the steps of, first, providing a first tobacco smoke filter segment made according to the present invention, and then affixing the first tobacco smoke filter segment to a body of divided tobacco. The method can further comprise the step of affixing a second tobacco smoke filter segment that is substantially free of copper-containing porphyrin to the body of divided tobacco. In a preferred embodiment, the second tobacco smoke filter segment affixed to the body of divided tobacco comprises cellulose acetate fibers treated with triacetin.
According to one embodiment of the present invention, there is provided a tobacco smoke filter comprising a first tobacco smoke filter segment made according to the present invention. The tobacco smoke filter can also comprise a second tobacco smoke filter segment that is substantially free of copper-containing porphyrin. According to another embodiment, there is provided a smokable device comprising the tobacco smoke filter according to the present invention affixed to a body of divided tobacco.
According to one embodiment of the present invention, there is provided a method of filtering tobacco smoke. The method comprises the steps of providing the smokable device of according to the present invention, igniting the body of divided tobacco such that smoke passes through the body of divided tobacco and into the filter, and allowing the smoke to pass through the filter thereby filtering the smoke.
The present invention further comprises an iron analog of C.I. Reactive Blue 21 dye and methods, tobacco smoke filters and smokable devices of the present invention, where the iron analog of C.I. Reactive Blue 21 dye is substituted for the copper-containing porphyrin. Additionally, there is provided.